Old Mutual MyPortfolio error

An internet search, trying to determine if others have had the same issues I'm experiencing, lead me to this site; and from a previous review it turns out that the problem goes back at least as far as 2018 (Dietrich M, 05 Dec. 2018). For the past week I've been battling with Old Mutual to fix access to my online profile: As things currently stand, I'm able to log in but have no access to my investment portfolio, can not manage my investment, in fact I can't even view my investment details. After a call with Old Mutual support I was informed in an email that it had been fixed. After replying that the problem persists on my side, I was contacted again and informed that it works, which it still doesn't. Now I use Firefox on Linux, and the first thing being told by the consultant during the initial phone call was that only Chrome and Edge/IE would work (the website also displays a message that the site has been optimised for IE). Well, I ended up testing on Firefox and Chrome (in both Linux and Windows) and with Edge and IE on Windows, without any luck. I even ended up downloading the mobile app and unsurprisingly, it also refuses me access to my portfolio. Since Old Mutual can not provide me with a reliable and convenient means of managing my investment, my next step will be to terminate it by any means possible, and add these funds to my investments managed by Nedgroup, who BTW has a website that works flawlessly regardless of the browser or OS being used; if they can do it, why can't you, Old Mutual?